Machines such as motors and generators typically include a control system for regulating various parameters in the machine. For example, a motor may include a control system that regulates the torque or speed of the motor to prevent the motor from overheating. Similarly, a generator may include a controller that regulates the current or voltage produced by the generator.
Various circuits and methods are known in the art for controlling machines. For example, a control system may operate essentially according to trial and error by issuing a control signal to alter the operation of the machine and then varying the magnitude of the control signal based on the machine's response to the control signal. For example, a controller attempting to raise the output voltage of a generator may issue an initial control signal and then adjust that initial control signal depending on the resulting change in the output voltage of the generator. While simple in its methodology, this trial and error approach typically requires more time to achieve the desired operating level of the machine, and it may result in excessive hunting until the machine stabilizes at the desired operating level.
To avoid the disadvantages of trial and error, some control systems may include programming or circuitry that models the operation of the machine. The control system accesses the programming or circuitry to generate an appropriate control signal that efficiently and precisely alters the machine operation to produce the desired parameter value. In some cases, the programming or circuitry may be generic to an entire class of machines, while in other cases, the programming or circuitry may be specifically tailored to each type of machine, or, more particularly, to an individual machine in a class of machines.
The ability of the control system to accurately and efficiently regulate the machine is directly dependent on the ability of the programming or circuitry to accurately model the operation of the particular machine. For example, in the field of wind turbine generators, many different generator designs exist to allow the optimum production of power in varying environmental situations. Many differences (e.g., the length, balance, and pitch of the rotating blades) exist between the various generator designs and even between individual generators in each design. In addition, variables unique to each installation (e.g., wind speed, atmospheric pressure, and humidity) may change over time or between seasons to vary the performance of individual generators. Lastly, changes in the generator over the life of the generator (e.g., friction, corrosion, changes in balance) may alter the operating characteristics of the generator.
Therefore the need exists for an improved control system for machines. Ideally, the improved control system may include a model of the machine's operating characteristics that can be updated or adjusted to reflect the actual performance of the machine over time.